Fuse and AC / DC distribution network leakage protection device

Abstract

The present invention discloses a fuse and an AC / DC power distribution network leakage protection device. The present invention provides an arc processor in a housing. When a strong arc is generated by the discharge of a molten block, the air pressure generated by blowing and sucking air stretches and cuts the arc, thereby extinguishing most of the arc. The remaining small part of the unextinguished arc and the weak arc generated by the fuse move along a tortuous flow channel, thereby lengthening the arc's free distance and time, greatly reducing the arc's breakdown force, and thus preventing the fuse from being broken down.

Description

Technical Field

[0001] The invention relates to a fuse and an AC / DC power distribution network leakage protection device, belonging to the field of leakage protection. Background Art

[0002] Leakage protection devices (LPDs) in AC and DC distribution networks are designed to detect and determine leakage current, but not to disconnect or connect the main circuit. They disconnect the circuit by melting the fuse element. When a load event occurs in the AC or DC distribution network, the fuse element discharges continuously for a short period of time. This discharge generates a transient, strong arc, which can easily penetrate the fuse's sealing cover, damaging the seal. Summary of the Invention

[0003] The present invention provides a fuse and an AC / DC power distribution network leakage protection device, which solve the problems disclosed in the background technology.

[0004] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0005] A fuse includes a housing and a frit disposed within the housing, an arc processor disposed between the frit and the end of an inner cavity of the housing, a fuse connected to the end of the frit near the arc processor, and a front end of the fuse passing through the arc processor and out of the end of the housing;

[0006] The arc processor includes a body, which is provided with a flow cavity and a zigzag flow channel. The fuse passes through the flow cavity. The zigzag flow channel connects the flow cavity and the inner cavity of the shell. A piston air supply device is provided at the connection between the zigzag flow channel and the inner cavity of the shell. Under the action of a strong electric arc, the piston air supply device blows air toward the inner cavity of the shell and the zigzag flow channel. Under the action of its own reset structure, the piston air supply device draws air from the inner cavity of the shell and the zigzag flow channel.

[0007] A pressure plate is also provided between the arc processor and the end of the inner cavity of the shell.

[0008] The tortuous flow channel and the flow cavity are connected via a tortuous flow hole.

[0009] The piston air supply device includes an air supply chamber and a push shaft. The rear end of the push shaft is located in the inner cavity of the shell, and the front end of the push shaft is embedded from the rear end of the air supply chamber. The front end of the push shaft is connected to a piston matching the air supply chamber. The front end of the air supply chamber is provided with several air outlets, and the rear end of the air supply chamber is provided with a reset block for resetting the push shaft.

[0010] There are multiple air vents, each of which is provided with a one-way flap. Some of the one-way flaps are opened when blowing air, and the remaining one-way flaps are opened when sucking air.

[0011] A regulator is provided at the end of the shell, and the regulator includes a base plate provided at the end of the shell and a lifting plate provided on the base plate. A winding column is provided on the base plate. Both the base plate and the lifting plate have through holes. The fuse passing through the shell passes through the through hole on the base plate, is wound on the winding column, and passes through the through hole on the lifting plate in sequence.

[0012] Two opposite squeezing rollers are rotatably connected in the through hole on the lifting plate.

[0013] The shell comprises a shell and sealing caps arranged at both ends of the shell. An active cavity is arranged in the sealing cap, and a plurality of elastic members are arranged in the active cavity.

[0014] A leakage protection device for an AC / DC distribution network, characterized by the fuse.

[0015] The beneficial effects achieved by the present invention are as follows: an arc processor is arranged in the shell of the present invention. When a strong arc is generated by the discharge of the molten block, the air pressure generated by the blowing and suction wind stretches and cuts off the arc, thereby extinguishing most of the arc. The remaining small part of the unextinguished arc and the weak arc generated by the fuse move along the tortuous flow channel, so that the free distance and time of the arc are lengthened, which greatly reduces the arc breakdown force, thereby preventing the fuse from being broken down. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural diagram of the fuse;

[0017] Figure 2 It is a structural diagram of the arc processor;

[0018] Figure 3 It is a structural diagram of the piston air supply device;

[0019] Figure 4 It is the structural diagram of the regulator;

[0020] Figure 5 This is a structural diagram of the leakage protection device for AC and DC distribution networks. DETAILED DESCRIPTION

[0021] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention.

[0022] like Figure 1 As shown, a fuse includes a shell and a sheet-shaped frit 5 fixed in the shell, an arc processor is fixed between the frit 5 and the end of the shell cavity, the end of the frit 5 close to the arc processor is connected to the fuse 6, the front end of the fuse 6 passes through the arc processor 7 and exits from the end of the shell, the end of the shell is fixed with an adjuster 8, and the fuse 6 that passes through the adjuster 8 is connected to the external contact box d or the AC block e.

[0023] The fuse has an overall symmetrical structure in the upper and lower parts, with a frit 5 in the center, fuses 6 connected to both ends of the frit 5, arc processors 7 at both ends of the frit 5, and regulators 8 at both ends of the outer shell. The fuse 6 of the upper regulator 8 is connected to the external contact box d, and the fuse 6 of the lower regulator 8 is connected to the external AC block e.

[0024] The shell of the fuse includes a shell 1 and a sealing cap 2 fixed at both ends of the shell 1. An active cavity is opened in the sealing cap 2, and a number of elastic parts are arranged in the active cavity. The elastic parts here include a first spring 4 and an inflatable ball 3. The two ends of the first spring 4 are connected to the upper and lower sides of the active cavity. The inflatable balls 3 are scattered in the active cavity. These elastic parts reduce the pressure on the sealing cap 2 to prevent the sealing cap 2 from being punctured.

[0025] like Figure 2 As shown, the arc processor 7 includes a body, and a pressure plate 9 is inserted between the body and the end of the inner cavity of the shell. The pressure plate 9 is a plate-like structure made of stone surface, which can prevent the arc from directly impacting the sealing cap 2. A flow cavity 10 and a tortuous flow channel 11 are provided inside the body. The flow cavity 10 is located in the middle of the body. The cavity wall is coated with a quartz sand layer to limit the arc generated by the fuse 6. The fuse 6 passes through the flow cavity 10. The number of tortuous flow channels 11 depends on the actual situation. Figure 2 There are two of them, symmetrically distributed on both sides of the flow cavity 10, and the tortuous flow channel 11 is connected to the flow cavity 10 through the tortuous flow hole, and the tortuous flow channel 11 is also connected to the inner cavity of the shell, and the connection point between the two is located on the body wall near the frit 5.

[0026] A piston air supply device 12 is detachably installed at the connection point between the zigzag flow channel 11 and the inner cavity of the shell. Under the action of a strong electric arc, the piston air supply device 12 blows air toward the inner cavity of the shell and the zigzag flow channel 11. Under the action of its own reset structure, the piston air supply device 12 draws air from the inner cavity of the shell and the zigzag flow channel 11.

[0027] like Figure 3 As shown, the piston air supply device 12 includes an air supply chamber and a push shaft 19. A baffle 15 is fixed in the air supply chamber to divide the air supply chamber into a first air supply chamber 13 and a second air supply chamber 14. A ventilation hole is provided on the baffle 15 to connect the first air supply chamber 13 and the second air supply chamber 14.

[0028] A plurality of air outlets 16 are provided at the front end of the second air supply chamber 14, and one-way flaps 17 are installed on the air outlets 16. Some of the one-way flaps 17 are folded when blowing air to open the air outlets 16 where they are located, and the remaining one-way flaps 17 are folded when sucking air to open the air outlets 16 where they are located. Generally, the two types of one-way flaps 17 can be arranged at intervals.

[0029] The rear end of the push shaft 19 is fixed with a push plate 21. The rear end of the push plate 21 has a circular groove 22 to facilitate air pressure to push the push shaft 19. The front end of the push shaft 19 is fixed with a piston 18 that matches the first air supply chamber 13. The front end of the push shaft 19 is inserted from the rear end of the first air supply chamber 13. The rear end of the first air supply chamber 13 is fixed with a reset block 20 that resets the push shaft 19. The reset block 20 includes a rubber outer sleeve and a second spring 29 enclosed in the outer sleeve.

[0030] After the push shaft 19 is pressurized, the piston 18 moves forward in the first air supply chamber 13, and the air pressure generated pushes part of the one-way flap 17 to open, blowing air into the inner cavity of the shell and the zigzag flow channel 11. When the push plate 21 of the push shaft 19 squeezes the reset block 20 to a certain extent, the reset block 20 applies a reverse force to the push shaft 19, and the piston 18 moves backward in the first air supply chamber 13. The negative pressure generated pushes the remaining one-way flap 17 to open, sucking air from the inner cavity of the shell and the zigzag flow channel 11.

[0031] When a strong arc is generated by the discharge of the molten metal 5, the strong arc pushes the push shaft 19 forward, and the piston air supply device 12 blows air into the housing cavity and the zigzag flow channel 11. The air pressure generated by the blowing and suction stretches and cuts the arc. When the push plate 21 of the push shaft 19 squeezes the reset block 20 to a certain extent, it pushes the push shaft 19 backward, and the piston air supply device 12 sucks air from the housing cavity and the zigzag flow channel 11, blowing the arc again, stretching and cutting the arc again, thereby extinguishing most of the arc. The remaining small part of the arc that has not been extinguished moves from the housing cavity into the zigzag flow channel 11, extending the arc's free distance and time, and significantly reducing the arc's breakdown force. When a weak arc is generated by the fuse 6, the flow cavity 10 confines the arc within the cavity, causing the arc to move along the zigzag flow channel 11, extending the arc's free distance and time, and significantly reducing the arc's breakdown force, thereby preventing the fuse from breaking.

[0032] like Figure 4 As shown, the regulator 8 includes a base plate 23 fixed to the end of the housing and a lifting plate 24 fixed to the base plate 23. A winding column 26 is installed on the base plate 23 for winding excess fuse 6. Through holes 28 are provided on the base plate 23 and the lifting plate 24. The fuse 6 passing through the housing sequentially passes through the through hole 28 on the base plate 23, is wound on the winding column 26, and passes through the through hole 28 on the lifting plate 24.

[0033] Two opposite squeezing rollers 27 are rotatably connected in the through hole 28 on the lifting plate 24 , and the fuse 6 passing through the through hole 28 is straightened by the squeezing rollers 27 .

[0034] There are many lifting structures of the lifting plate 24, such as screw rods, scissor-type lifting, etc. Here, a simple stud 25 is used. Relative connecting columns are fixed on the base plate 23 and the lifting plate 24, and screw holes are opened on the connecting columns. The total length of the two screw holes is greater than the stud 25, and the two ends of the stud 25 are screwed into the screw holes.

[0035] When the end of the fuse 6 connected to the contact box d or the AC block e is excessively worn, the worn section of the fuse 6 is cut off, the stud 25 is rotated to raise the lifting plate 24 so that it does not abut against the winding column 26, and a fuse 6 of an appropriate length is unwound from the winding column 26. The stud 25 is rotated to lower the lifting plate 24 so that it abuts against the winding column 26, and the unwound fuse 6 is pulled out from the through hole 28 on the lifting plate 24. The unwound fuse 6 is straightened by the squeezing roller 27, and the straightened fuse 6 is connected to the contact box d or the AC block e.

[0036] The adjuster 8 uses the winding post 26 to wind the redundant fuse 6. When the end of the fuse 6 is excessively worn, there is no need to replace the entire fuse, and only the appropriate fuse 6 needs to be unwound.

[0037] like Figure 5 As shown, a leakage protection device for an AC / DC distribution network includes an operating box a and a control box b fixed to one side of the operating box a. The control box b is equipped with the above-mentioned fuse c, a contact box d located at the upper end of the fuse c, and an AC block e located at the upper end of the fuse c. The contact box d and the AC block e are connected to the fuse 6 extending from the fuse c.

[0038] Of course, the control box b also includes a mutual inductance block f, a combination line h, and a trip block g for the snap-on combination line h, etc. Since these components and their connection relationships are existing structures, they are not described in detail here.

[0039] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A fuse comprising a housing and a frit disposed in the housing, characterized in that: An arc processor is provided between the frit and the end of the inner cavity of the shell. A fuse is connected to the end of the frit close to the arc processor. The front end of the fuse passes through the arc processor and out of the end of the shell. The arc processor includes a body, wherein a flow cavity and a zigzag flow channel are provided in the body, a fuse passes through the flow cavity, the zigzag flow channel connects the flow cavity and the inner cavity of the shell, and a piston air supply device is provided at the connection between the zigzag flow channel and the inner cavity of the shell. The piston air supply device blows air into the zigzag flow channel under the action of a strong arc, and the piston air supply device draws air from the zigzag flow channel under the action of its own reset structure; The piston air supply device includes an air supply chamber and a push shaft. The rear end of the push shaft is located in the inner cavity of the shell, and the front end of the push shaft is embedded from the rear end of the air supply chamber. The front end of the push shaft is connected to a piston matching the air supply chamber. The front end of the air supply chamber is provided with several air outlets, and the rear end of the air supply chamber is provided with a reset block for resetting the push shaft.

2. A fuse according to claim 1, characterized in that: A pressure plate is also provided between the arc processor and the end of the inner cavity of the shell.

3. A fuse according to claim 1, characterized in that: The tortuous flow channel and the flow cavity are connected via a tortuous flow hole.

4. A fuse according to claim 1, characterized in that: There are multiple air vents, each of which is provided with a one-way flap. Some of the one-way flaps are opened when blowing air, and the remaining one-way flaps are opened when sucking air.

5. The fuse according to claim 1, characterized in that: A regulator is provided at the end of the shell, and the regulator includes a base plate provided at the end of the shell and a lifting plate provided on the base plate. A winding column is provided on the base plate. Both the base plate and the lifting plate have through holes. The fuse passing through the shell passes through the through hole on the base plate, is wound on the winding column, and passes through the through hole on the lifting plate in sequence.

6. A fuse according to claim 5, characterized in that: Two opposite squeezing rollers are rotatably connected in the through hole on the lifting plate.

7. A fuse according to any one of claims 1 to 6, characterized in that: The shell comprises a shell and sealing caps arranged at both ends of the shell. An active cavity is arranged in the sealing cap, and a plurality of elastic members are arranged in the active cavity.

8. An AC / DC distribution network leakage protection device, characterized in that: A fuse comprising the fuse according to any one of claims 1 to 7.

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